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Topic: over heating problem (Read 1247 times) previous topic - next topic

over heating problem

ok heres my prob.  I changed the thremostat, flushed it, changed the water pump! and the temp still creeps up to pass normal. the only thing i haven't done is put a brand new radiator in it.  so what could the prob be. i know the timing is fine that was the last op.  its a 3.8 engine for those that can assist me with this. thanx

Re: over heating problem

Reply #1 –
Have you replaced the fan clutch?  If the problem happens at idle or at low rpms that could be it.  If it is happening on the highway it could be a problem with the front air dam that directs the air onto the radiator, might be blocked or something.
Foxless :(

Re: over heating problem

Reply #2 –
OK, I tell ya what. I live in south Florida, just about one of the hottest places one of these things can run outside of MexCougar's neighborhood.. and I think I've stumbled onto my best setup yet for my 3.8.

When the clutch fan on my 3.8 ped out, I picked up a reverse-rotation 18" flex fan. Yeah, it cooled.. but it was loud as hell, and it made the engine a little less responsive. (also made the belts chirp when I would stab the pedal) Well finally I decided I would swap the flex fan with the (working) clutch fan on my '88 5.0. It was a tight fit on the shroud, (you have to be careful or it will rub) but it's been one change I'm really glad I made.

Before, when I would idle for awhile in a parking lot with the A/C running, the temperature would creep up toward 210+. Now, if I do the same thing, the temperature stays right around 192, which is what my thermostat is rated for.

At the very least, I suggest snagging a new clutch.. but if you can get hold of a clutch fan from a 5.0, (the plastic ones) I say go for it.

Re: over heating problem

Reply #3 –
personally im just ready to trash the whole car.  Its like the top hose is being restricted water flow.  when its over heating its like pressure in the top hose and it looks like its not passing thru thremostat part. when u squeeze the hose it just feels like its ready to burst. u can barely squeeze it. im all guessed out.

Re: over heating problem

Reply #4 –
bypass the heater core looping the two hoses back to each other
spin the fan by hand with engine cold, should only spin about 3/4 of a turn
do you have to loose coolant?

park you car with the nose up and add coolant
squeeze the upper hose while putting your hand on the radiator cap opening
add fluid till all the air is out of the system

Re: over heating problem

Reply #5 –
have you replaced the Water Temp sensor, for the 6 bucks, I would check to make sure it's not bad. also, do like jcassity said, make sure there are no air bubbles in your system.

Re: over heating problem

Reply #6 –
Quote from: knockout ned
when its over heating its like pressure in the top hose and it looks like its not passing thru thremostat part. when u squeeze the hose it just feels like its ready to burst. u can barely squeeze it. im all guessed out.

That is normal, the hose is pressurized to ~15 psi. If there were a flow restriction, the hose would be very easy to squeeze, since there wouldn't be much fluid flowing through it.

Does it overheat at idle, on the interstate, or both? Have you looking in the radiator to see the condition of the radiator core?

Re: over heating problem

Reply #7 –
thanx guys for the help. after all that trouble, come to find out it was the  radiator after all. took the one out the t-bird to see if that was an issue and of course it was.

Re: over heating problem

Reply #8 –
How about a post mortem on this topic... (cause I'm having similar troubles)

So how does a radiator "go bad"?  Is there any way of telling by looking at it??


V6->V8HO 88 LS
5.0L V8 87 XR7

Re: over heating problem

Reply #9 –
Quote from: bondocougar
How about a post mortem on this topic... (cause I'm having similar troubles)

As I said earlier, does it overheat at idle, at speed, or both?

Quote
So how does a radiator "go bad"?  Is there any way of telling by looking at it??

Most radiators "go bad" from a buildup of scale. The scale reduces the ability of the radiator to transfer heat out of the coolant and restricts flow. If your vehicle only overheats at speed, the radiator is the most likely culprit. A missing air dam can also cause overheating at speed. Overheating at idle can be caused by a bad fan clutch. If the fan clutch tests good, the radiator is then the most likely culprit. Look at the radiator core through the radiator cap opening to see the condition of the core. Some buildup is normal.